Preparing Highly Fluorinated Multiwall Carbon Nanotube by Direct Heating-Fluorination during the Elimination of Oxygen-Related Groups

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• 作者：Xu Wang ; Yi Chen ; Yunyang Dai ; Qin Wang ; Jie Gao ; Jieyang Huang ; Jin Yang ; Xiangyang Liu
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：June 13, 2013
• 年：2013
• 卷：117
• 期：23
• 页码：12078-12085
• 全文大小：450K
• 年卷期：v.117,no.23(June 13, 2013)
• ISSN：1932-7455

文摘

Pristine and oxidized multiwalled carbon nanotubes (MWCNTs) were separately prepared and directly fluorinated with F<sub>2sub> through two different routes: heating-fluorination and isothermal-fluorination. The amount of fluorine atoms (hereinafter referred to as 鈥淔-content鈥? bonding to the fluorinated samples was largely dependent on the modifing route and chemical bonding of MWCNTs. The F-content of heating-fluorinated pristine and oxidized MWCNTs was 3.2% and 9.2% respectively, which were about 8 times and 18 times that of the corresponding isothermal-fluorinated MWCNTs. According to structural analysis of samples before and after fluorination, it was found that thermal elimination of oxygen-related groups bonding to MWCNTs contributed to the formation of strongly covalent C鈥揊 bonds during heating-fluorination. It was considered that the oxygen-related groups provided reactive sites for the fluorination. The fluorination reaction took place at an sp<sup>3sup> carbon linking with the oxygen-related groups and did not increase the density of defect on MWCNTs. A radical-mediated mechanism is accepted for this reaction. Thus, MWCNTs could be first oxidized to increase the number of oxygen-related groups and then heating-fluorinated by F<sub>2sub> directly to get highly fluorinated MWCNTs with stable C鈥揊 bonds.